I. Field of the Invention
This invention relates to the securement of glass in fire doors and the like. More particularly, the invention relates to such securement avoiding the use of visible metal parts.
II. Description of the Prior Art
The use of windows or lights in fire doors is advantageous because a person escaping from a fire can immediately see whether it is safe to open the door or whether the fire is worse on the other side. Furthermore, as fire doors usually have to be kept closed at all times, the presence of windows or lights provides a building with a less claustrophobic appearance.
The disadvantage of the use of windows or lights in fire doors is that they can reduce the ability of the door to prevent the spread of fire. Heat-resistant glass can be employed, but the frame around the glass is susceptible to burning. To overcome this, metal frames are often provided around the windows or lights, but when the fire door itself is made of wood, this significantly reduces the attractiveness of the door. The use of metal frames can also be expensive.
It is therefore an object of the present invention to provide an alternative to the use of metal frames without reducing the fire retardancy of the door below specified levels.